This invention relates to an adjustable mechanism featuring a non-continuous ring member which encircles a circular journal portion, end parts in the ring member being displaceable either to tighten or to loosen the ring member with respect to the journal portion it encircles. With the ring member loosened, it is rotatable relative to the journal portion, and with the member tightened, it becomes frictionally secured to the journal portion.
In the particular embodiment of the invention herein specifically disclosed, the adjustable mechanism provides a mounting for a support arm, with the support arm providing support for such an instrumentality as a reading lamp, a work table, electronic instrumentation, etc. However, by specifically illustrating and describing the mechanism in conjunction with a support arm, it is not intended to so limit the invention, as the mechanism has useful applicability where it is desired controllably to release and lock one member with respect to another.
An object of the invention, therefore, is to provide a novel adjustable mechanism which includes a non-continuous ring member encircling a journal portion, the ring member being adjustably positionable with respect to the journal portion on relative displacement of ends in the ring member.
More specifically, the invention contemplates such a mechanism which includes a lever member with portions mounted on respective end parts of the ring member. The lever member is swingable in one direction to produce tightening of the ring member and in the opposite direction to produce loosening. The mechanism further includes adjustable means interposed between these end parts adjustable to permit the lever to move in a tightening direction without producing the normally expected tightening.